Prosecution Insights
Last updated: April 19, 2026
Application No. 18/550,562

BASE OIL COMPOSITION, FORMULATION AND USE

Non-Final OA §102§103
Filed
Sep 14, 2023
Examiner
OLADAPO, TAIWO
Art Unit
1771
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Equus UK Topco Ltd.
OA Round
4 (Non-Final)
53%
Grant Probability
Moderate
4-5
OA Rounds
3y 2m
To Grant
64%
With Interview

Examiner Intelligence

Grants 53% of resolved cases
53%
Career Allow Rate
605 granted / 1144 resolved
-12.1% vs TC avg
Moderate +11% lift
Without
With
+11.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
89 currently pending
Career history
1233
Total Applications
across all art units

Statute-Specific Performance

§101
0.9%
-39.1% vs TC avg
§103
52.8%
+12.8% vs TC avg
§102
16.2%
-23.8% vs TC avg
§112
15.9%
-24.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1144 resolved cases

Office Action

§102 §103
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Claim Interpretation Claim 41 recites poly (alkoxy ether) which according to page 7 of applicant’s specification is not a separate ingredient in the oil but is part of the ingredients for making the ester of formula (I) of the claim. Thus, the recitation of poly (alkoxy ether) is interpreted in view of the specification the component used in preparing the diester of formula (I) of claim 37. Hence, claim 41 is a product by process claim. Claim Rejections - 35 USC § 102/103 The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 37, 38, 41 – 47, 49 – 52, 54 are rejected under 35 U.S.C. 102(a)(1) as anticipated by Forbus (US 2017/0145336) or, in the alternative, under 35 U.S.C. 103 as obvious over Forbus (US 2017/0145336) In regards to claim 37, Forbus teaches simple or complex carboxyl esters or mixtures comprising carboxyl end-capped-polytetramethylene glycols (abstract). Forbus teaches a lubricating fluid composition comprising diester of polytetramethylene glycol having a formula (1), wherein the groups R1 and R2 are linear alkyl groups having from 5 to 11 carbon atoms which are analogous to R of the claimed structure, and m is 2 to 4 and analogous m in the claimed structure, and the tetramethylene is a C4 linear alkylene which is analogous to X in the claimed structure, and thus provides the claimed base oil [0004]. Forbus teaches the use of the diester as base oil, and teaches that the R1 and R2 may each contain a branched group at less than 10%, or less than 5% [0018 – 0020]. The composition is suitable for providing the intended use limitation of the claim. In regards to claim 38, Forbus teaches the composition having the claimed limitation as previously discussed. In regards to claim 41, Forbus teaches the composition having the claimed limitation. The claim is drawn to a product by process step. So long as the ester compound is provided, the means of deriving the alkylene oxy group such as from bio or renewable resources used in forming the ester doesn’t carry patentable weight or is provided for in the ester compound itself. In regards to claim 42, Forbus teaches the composition having the compound with alkyl carbonyl having the claimed amounts of carbon atoms. In regards to claims 43 – 46, Forbus teaches the composition having the claimed limitation as previously stated. Product by process limitations is met when the product is taught. The means of providing the alkyl carbonyl groups from renewable or bio-based source does not carry patentable weight or is met as long as the final product is taught. In regards to claim 47, Forbus teaches the composition which is suitable for providing the intended use. Forbus teaches the composition is useful as gear oil [0035]. In regards to claims 49 – 51, Forbus teaches the composition which can comprise one or more additive ingredients of the claims [0027]. The additives are present in amounts such that the amount of the base oil will meet or overlap the claimed ranges [0028 – 0034]. For instance, while rust inhibitors are present at 0 to 37%, pour point depressant at up to 10%, dispersant at up to 7% or metal detergent at up to 5%, the additives as a whole may be present at smaller amounts totaling from 1 to 30% or from 2 to 15% [0035]. In regards to claim 52, Forbus teaches the composition having base oil blends with kinematic viscosity at 40℃ of from 15 to 1500 cSt which overlaps the claimed range [0023]. Even in the presence of optional additives the viscosity is majorly controlled by the oil in the absence of viscosity modifiers, or when they are used at minor amounts. In regards to claim 54, Forbus teaches the composition having the claimed limitation wherein the composition comprises base oil blends of a first diester according to formula I of the claim in mixture with a second diester which is dimeric acid (oleic dimer) diester having R groups that are outside of the claimed limitation (i.e., diester of a formula 2), and wherein the mixtures allow each base oil to be present in amounts overlapping the claimed range [0004, 0007 and 0050]. Claims 37 – 47, 49 – 51, 54 are rejected under 35 U.S.C. 102(a)(1) as anticipated by Tsubouchi (JP 2012-31359A) or, in the alternative, under 35 U.S.C. 103 as obvious over Tsubouchi (JP 2012-31359A) In regards to claims 37 – 47, Tsubouchi teaches a base oil drawn to a diester or a diether (abstract). The diester is prepared from linear or branched acids such as pentanoic acid, ethylhexanonic acid, tetradecanoic acid such as having C5 to C14 alkyl carboxyl groups, alcohol such as ethylene glycol, propylene glycol, butylene glycol etc., which provides diesters analogous to the formula I of the claim when R is alkyl carbonyl having C5 to C14 carbon atoms, m is at least 1, X is C2 or higher (specification). The oil is capable for providing the intended use of the claim. Tsubouchi teaches use of the composition in electric vehicles (specification). Limitations drawn to the materials used for preparing the diester such as from renewable or bio-sources do not carry patentable weight. In regards to claims 49 – 51, 54, Tsubouchi teaches the base oil can comprise 30% or more and up to 100% of the diester (specification). The base oil has a viscosity of from 4 to 30 cSt at 40℃ (specification). The composition can comprise various additives such as antioxidants, detergents, dispersant, VI improvers, antiwear etc. (specification). In the absence of VI improvers, or in the presence at the low amounts of about 0.1% as recited by Tsubouchi, the viscosity of the composition is essentially the viscosity of the base oil. While corrosion inhibitors are not particularly recited, they are customary additives which would have been obvious. Response to Arguments Applicant’s arguments have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to TAIWO OLADAPO whose telephone number is (571)270-3723. The examiner can normally be reached 8-5pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Prem Singh can be reached at 571-272-6381. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /TAIWO OLADAPO/Primary Examiner, Art Unit 1771
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Prosecution Timeline

Sep 14, 2023
Application Filed
Jun 13, 2024
Non-Final Rejection — §102, §103
Oct 02, 2024
Response Filed
Dec 05, 2024
Non-Final Rejection — §102, §103
Mar 10, 2025
Response Filed
May 22, 2025
Final Rejection — §102, §103
Aug 28, 2025
Response after Non-Final Action
Oct 28, 2025
Applicant Interview (Telephonic)
Oct 28, 2025
Examiner Interview Summary
Feb 13, 2026
Non-Final Rejection — §102, §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

4-5
Expected OA Rounds
53%
Grant Probability
64%
With Interview (+11.4%)
3y 2m
Median Time to Grant
High
PTA Risk
Based on 1144 resolved cases by this examiner. Grant probability derived from career allow rate.

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